The cancellation right stems from the right of Paul's appeal in Roman law.It has now become an important preservatory man-sure in the law of obligation.
Now the various countries mainly adopt two kinds of prosecutions patterns: One is the appeal monopolism,that is only the government can sued the criminal offender and the victim has no right to sue.
It's also worth noting that the memo explicitly says the charges will be dropped without prejudice, which means they could potentially be brought again.